1. Field of the Invention
The present invention relates to a liquid container and an ink jet printing apparatus and in particular, to a display control of light-emitting means such as a LED for indicating a mounting state or a liquid remaining amount of a liquid container such as an ink tank.
2. Description of the Related Art
There has been recently increasing a printing use (non-PC printing) due to spreading of digital cameras, in which the digital camera is directly connected to a printing apparatus not via personal computer (PC) for printing. There is also an increasing system where an information memory medium of a card type, which is an information memory medium used removably in the digital camera, is mounted directly to a printer for data transfer so as to perform printing (non-PC printing). There is well known a method of checking an ink remaining amount inside an ink tank of a printer on a monitor through a PC. Also in a case of performing the non-PC printing, there is an increasing demand for desiring of detecting the ink remaining amount inside the ink tank not via the PC. That is, if a user finds that the ink remaining amount inside the ink tank is small, the ink tank can be replaced with a new one before the printer starts a printing operation to prevent the situation where the printing can not be substantially made in the middle of the printing operation for lack of the ink.
There is known a system of using an indicating element such as a LED, as a structure of informing a user of such a state in the ink tank. Japanese Patent Laid-Open No. 4-275156 (1992) discloses a system where two LEDs are disposed in an ink tank integral with a printing head and respectively light up in accordance with two stages of an ink remaining amount. Japanese Patent Laid-Open No. 2002-301829 shows disposing in a tank a lamp which turns on in accordance with an ink remaining amount and also discloses a structure of disposing the lamp in each of four ink tanks used in a printing apparatus.
On the other hand, ink such as light magenta or light cyan having a lower concentration of coloring material has begun to be used in addition to conventional ink of four colors (black, yellow, magenta and cyan) in view of a demand for a higher image quality. In addition, ink of a particular color such as red or blue ink has been provided. In these cases, 7 or 8 ink tanks are to be mounted individually to an ink jet printer. On this occasion, it requires a mechanism for preventing the ink tank from being mounted in a wrong position.
In a case where a lamp is disposed in an ink tank, the ink tank where an ink remaining amount is small is required to be identified so that a signal for turning on the lamp is transmitted to the corresponding ink tank. When the ink tank is mounted in a wrong position, it has the possibility of displaying in the wrong that there is no ink remaining amount in the ink tank where the ink still remains in amount. Accordingly, a light-emitting control for a display such as a lamp is required to identify the mounting position of the ink tank.
Here, an example of structure for identifying mounting positions of ink tanks is shown as follows. Electrical contacts with which ink tank is equipped contact with electrical contacts with which a printer main body is equipped at a mounting position of a carriage or the like. The structure is adapted to set a signal line of a circuit formed by such contact as an individual signal line for each mounting position of the ink tanks. For example, a signal line for reading out ink color information of an ink tank from the corresponding ink tank and controlling lighting of a LED or the like is provided as an individual signal line for each mounting position of the ink tanks. According to this structure, when the read-out color information does not correspond to the mounting position of the ink tank, it results in that the ink tank is mounted in the wrong.
The structure where such signal line is individually disposed for each ink tank or each mounting position of the ink tanks leads to an increase of the number of signal lines. In particular, in a printer to use many kinds of ink tanks, the increasing number of signal lines is the cause of cost-up.
Japanese Patent Laid-Open No. 2006-142484 shows a structure of using a common signal line such as a bus connection for identifying an ink tank or performing display control of a display. Such bus connection helps in eliminating the number of wires, so that even when the number of ink tanks mounted increases as described above, it is possible to restrict an increase in costs.
Japanese Patent Laid-Open No. 2006-142484 describes a structure in which, for receiving and transmitting signals between a printer main body and an ink tank, color information of a tank is added to a data signal. According to the structure, the ink tank of the corresponding ink color recognizes the color information to recognize that the data signal is directed to itself. In addition, the printer main body recognizes the color information of the tank to recognize that the data signal relates to data from the ink tank of the corresponding color associated. For example, in a case of performing display control for an ink tank, first the printer main body identifies the ink tank based on the color information, and thereafter, transmits a control code associated with the display. Thereby, turning-on or turning-off of a LED can be made only with the side of the corresponding ink tank. While moving a carriage with the ink tank being mounted, lighting is performed at determined timing only in the corresponding ink tank. A sensor is disposed in a specified position along a moving path of the carriage. Whether or not the ink tank of the corresponding color is mounted in a correct position can be recognized depending on whether or not this sensor has detected the lighting of the ink tank at the determined timing.
In this way, the structure of using the bus connection for the signal line is advantageous in identifying the ink tank or performing the display control.
In a case of making communication between the printer main body and the ink tank by using the bus connection, however, it may be hard to identify the ink tank. This is a case where a user fails to distinguish among tanks and mounts a plurality of tanks having the same ink color. For example, this is a case where an ink tank of cyan ink is mounted in a correct position and another ink tank of the same cyan ink is wrongly mounted in a mounting position of an ink tank of blue ink. In this way, when the plural tanks of the same ink color are mounted, by the bus connection of the signal line, the same “color information” is added to a data signal and is then transmitted to the ink tanks. In this case, a plurality of ink tanks receive the same “color information”, and then it is not possible to distinguish the mounted tanks of the same ink color from each other.
It is advantageous to detect that plural ink tanks of the same color are mounted by using a signal connection structure of the same bus connection without providing a new signal connection and to inform a user of the corresponding ink tank by the individual indication. This is because the problem with deterioration of a printed image due to wrong mounting of an ink tank can be prevented without attention by a user being paid so much.